Searching for liquid water on exoplanets is key to finding life among stars, but scientists have now proposed a new strategy that could improve the chances of finding life.
In a new study published Dec. 28 in the journal natural astronomyresearchers believe that if the atmosphere exoplanet With less CO2 than its neighbors, there could be vast amounts of water and even life on its surface.
Currently, finding liquid water on planets outside our solar system is a major challenge. Of the approximately 5,000 exoplanets we have discovered, none have been found to contain liquid water.The best thing scientists can do is detect traces of water exoplanet atmosphere Determine whether a planet will form theoretically supported water in liquid state.
“We now know that Earth’s atmosphere was initially composed mostly of CO2, but then carbon dissolved into the oceans, allowing Earth to support life for the past four billion years or so,” said the study’s co-lead authors. Professor Amaury Tryau said. Doctors in exoplanetology at the University of Birmingham, UK, said in a statement:
When carbon dissolves in the ocean, tectonic activity traps it in the Earth’s crust, creating an effective carbon sink. This is one reason why our planet has significantly lower CO2 levels compared to neighboring countries. The Earth’s atmosphere has a CO2 concentration of about 0.04%; Venus and Mars Both contain over 95% CO2.
If scientists observe similar low-carbon atmospheres on exoplanets, it could indicate the existence of vast oceans similar to our own, the researchers said.
Finding CO2 is easier than finding liquid water. CO2 absorbs infrared light well. That is, it produces a strong signal that scientists can detect.
This technique can also be performed with existing telescopes such as: james webb space telescope (JWST). Since CO2 is measured at specific wavelengths, it should also be possible to observe it from the ground, but Earth’s atmosphere partially absorbs the signal, allowing experiments at other wavelengths.
“This is a really great way to do it, and you don’t have to invest a huge amount of time into a telescope, which is really important because it’s so valuable to our community,” he said. sarah casewellHe is a lecturer in the Department of Physics and Astronomy at the University of Leicester in the UK, but was not involved in the research.
Interestingly, another scenario could contribute to a low-carbon atmosphere, and therefore life itself. The main ways life on our planet captures carbon is through photosynthesis and the formation of shells. 20% Of all the carbon capture on Earth, biological processes cause it.
“Despite early expectations, most of our colleagues ultimately concluded that major telescopes like JWST cannot detect life on exoplanets. Our research is a new “This brings us great hope,” said the study’s co-lead authors. Julien de Witsaid the Massachusetts Institute of Technology assistant professor of planetary science in a statement. “By exploiting the signature of carbon dioxide, we can not only infer the presence of liquid water on distant planets, but also provide a path to identifying life itself,” de Witt said.
Although this approach seems to work in principle, there may still be hurdles, as it is unclear how many Earth-like exoplanets have atmospheres. “Finding the best system to test this may prove to be a little more difficult than we previously thought,” Casewell told his Live Science.
But as researchers continue to discover more exoplanets, more atmospheres will also be discovered. And this technology could help determine whether they can sustain life.